Nowadays, car navigation systems have an ITS (Intelligent Transport System) on-vehicle device which includes a navigation apparatus mounted on a vehicle and provide many kinds of services such as the ETC (Electronic Toll Collection system) and the VICS (Vehicle Information and Communication System).
Recently, there have been attempts to provide various services by adopting a wireless communication protocol called a DSRC (Dedicated Short-Range Communication) system. In order to provide such services, a roadside radio device and a center apparatus both of which are capable of the DSRC connection must be capable of communicating with each other over a network. The roadside radio device is disposed at a predetermined point and communicates with the navigation apparatus over the DSRC connection. The center apparatus, in turn, sends information stored therein for use in providing services, to the roadside radio device if required.
With the DSRC, community-based advertisement information can be displayed on the screen of the navigation apparatus in real time as well as the above-mentioned ETC and VICS. The community-based advertisement information includes information on various facilities such as restaurants, parking lots, and the like around the vehicle. With such an advertisement distribution service using the DSRC, the user can watch only necessary advertisement information on the area around the vehicle on the screen of the navigation apparatus (see Patent Document 1, and Patent Document 2).
Patent Document 1: Japanese Patent Application Laid-Open No. 2001-101578
Patent Document 2: Japanese Patent Application Laid-Open No. 2004-279509